* Notify an newly assigned agent
 * @since 1.0.7

If you assign a new agent through the backend, this new agent will get a notification email. You can filter the subject of this mail via sts-notify-new-agent-subject, the mail text via sts-notify-new-agent-body and as usual, the ticket URL via sts-view-ticket-url.

This function utilizes sts-ticket-agent-updated.